图片上传与下载

private static final String IMAGE_TYPE_PROMPT = "文件格式仅支持jpg、png";
private static final String IMAGE_FILE_SIZE_PROMPT = "文件格式仅支持jpg、png";

public String saveUserImageToDir(MultipartFile multipartFile, String dir) throws AobpException, IOException {
    if (!ImageUtil.checkIsImgByName(multipartFile.getOriginalFilename())) {
        throw new AobpException(ExceptionConstant.PARAMS_INVALID, IMAGE_TYPE_PROMPT);
    }
    if (!ImageUtil.fileSizeLegal(multipartFile.getSize())) {
        throw new AobpException(ExceptionConstant.PARAMS_INVALID, IMAGE_FILE_SIZE_PROMPT);
    }
    return UploadUtil.upload(multipartFile,dir);
}

public class UploadUtil {

    /**
     * @return dest file name
     */
    public static String uploadFileToDir(MultipartFile multipartFile, String saveDir) throws AobpException {
        String fileName = UUID.randomUUID().toString().replaceAll("-", "");
        // 文件新路径：文件名
        uploadFileToDir(multipartFile, saveDir, fileName);
        return fileName;
    }

    public static void uploadFileToDir(MultipartFile multipartFile, String saveDir, String fileName) throws AobpException {
        uploadFile(multipartFile, saveDir + File.separator + fileName);
    }

    public static void uploadFile(MultipartFile multipartFile, String filePath) throws AobpException {
        try (InputStream inputStream = multipartFile.getInputStream();
             FileOutputStream outputStream = new FileOutputStream(filePath)) {
            IOUtils.copy(inputStream, outputStream);
        } catch (Exception e) {
            log.error("copy file failed", e);
            throw new AobpException(ExceptionConstant.INTERNAL_ERR, ExceptionConstant.UNKNOWN_ERROR);
        }
    }
    
    //用户上传相关Yao
    protected  static Map<String, String> getFilePath(String path, String originName){
        Date nowDate = new Date();
        String fileFolder = path+File.separator+new SimpleDateFormat("yyyy").format(nowDate)+
                                    File.separator+new SimpleDateFormat("MM").format(nowDate);
    
        File fileNew = new File(fileFolder);
        if(!fileNew.exists()){
            fileNew.mkdirs();
        }
        String fileName = new SimpleDateFormat("yyyyMMddhhmmssSSSS").format(nowDate)+(int)((Math.random()*9+1)*100000)+"."+originName.substring(originName.lastIndexOf(".")+1);
        String filePath = fileFolder+File.separator+fileName;
        Map<String, String > resultMap = new HashMap();
        resultMap.put("fileName",fileName);
        resultMap.put("filePath",filePath);
        return resultMap;
    }
    
    public static String  upload(MultipartFile file, String saveDir) throws IOException, AobpException {
        //如果文件内容不为空，则写入上传路径
        if (!file.isEmpty()) {
            //上传原文件名
            String originName = file.getOriginalFilename();
            Map<String, String> resultMap = getFilePath(saveDir, originName);
            File filePath = new File(resultMap.get("filePath"));
            try(FileOutputStream fileOutputStream = new FileOutputStream(filePath)){
                FileCopyUtils.copy(file.getInputStream(), fileOutputStream);
            }
            return resultMap.get("fileName");
        }
        throw new AobpException(500, "图片上传失败");
    }
}